In less than a week, Washington County Sheriff's Office detectives have opened two cases involving unidentified human remains in Southern Utah.

Most recently, the remains of a female were found along the Virgin River about one mile north of the Arizona border. The body was found by a family recreating with off-road vehicles, and WCSO Lt. David Crouse said the body was in an advanced state of decomposition.

The identity of the female and the cause of death are not yet known, and Crouse said investigators are working with the Utah Medical Examiner's Office, comparing the decomposed body against any missing persons.

There were a few items of "potential evidence" collected at the scene, Crouse said, although nothing that initially identified the cause of death.

"We go based off the evidence that we have," Crouse said. "If we can't see that it's an accident or natural causes, all unattended deaths are treated as criminal investigations until we can rule otherwise."

The body was found about three miles west "as the crow flies" of any populated area.

Just six days prior, WCSO officials opened an investigation of another unattended death and unidentified male human remains in Washington City.

Additionally, the St. George Police Department wrapped up an investigation involving a woman's body that was found in a wash along the Santa Clara River earlier this month. The woman was later identified as Amy Marie Crawford of St. George.

Investigators do not have reason to believe the deaths of the two unidentified individuals are related, Crouse said.